Intrinsic properties of Fe(Se,Te), such as the high value of the upper critical field as well as the weaker dependence of the critical current density (Jc) on the grain misalignment than in cuprate superconductors, make this compound a promising candidate for the fabrication of high-field superconducting magnets. On the other hand, irradiation was demonstrated to be a powerful tool for tuning the pinning properties in superconducting materials. In this paper, we investigate the effect of 230 MeV Au-ion irradiation on Jc and pinning force (Fp) of biaxially-oriented Fe(Se,Te) films grown on YSZ substrate buffered with a thin Zr-doped CeO2 epitaxial layer. This structure is interesting as it can be considered a precursor template for Fe(Se,Te) coated conductors. The irradiation produces correlated defects, which - on transmission electron microscope analysis - appear as slightly meandering tracks composed of dislocation chains placed parallel to the c-axis of the crystal lattice. The Jc measurements as a function of the applied magnetic field evidence an improvement at low temperatures, with a maximum modulated in both position and height by the irradiation fluence. In the same range of temperature, the development of the irradiation tracks strongly reduces the anisotropy of the critical current density by varying the applied field orientation. Likewise, the Fp analysis highlights that irradiation defects behave as two-dimensional extended defects, which strengthen the point-pinning landscape active before irradiation. Conversely, approaching the transition temperature, the effectiveness of the irradiation-induced defects decreases and a widespread Jc and Fp worsening occurs.
Correlated Defect Formation and Pinning Enhancement in 230 MeV Au-Ion-Irradiated Superconducting Fe(Se,Te) Thin Films
Mario Scuderi;Valeria Braccini;Emilio Bellingeri;Michela Iebole;Alberto Martinelli;Nicola Manca;Matteo Cialone;Marina Putti;Maria Laura Amoruso;
2026
Abstract
Intrinsic properties of Fe(Se,Te), such as the high value of the upper critical field as well as the weaker dependence of the critical current density (Jc) on the grain misalignment than in cuprate superconductors, make this compound a promising candidate for the fabrication of high-field superconducting magnets. On the other hand, irradiation was demonstrated to be a powerful tool for tuning the pinning properties in superconducting materials. In this paper, we investigate the effect of 230 MeV Au-ion irradiation on Jc and pinning force (Fp) of biaxially-oriented Fe(Se,Te) films grown on YSZ substrate buffered with a thin Zr-doped CeO2 epitaxial layer. This structure is interesting as it can be considered a precursor template for Fe(Se,Te) coated conductors. The irradiation produces correlated defects, which - on transmission electron microscope analysis - appear as slightly meandering tracks composed of dislocation chains placed parallel to the c-axis of the crystal lattice. The Jc measurements as a function of the applied magnetic field evidence an improvement at low temperatures, with a maximum modulated in both position and height by the irradiation fluence. In the same range of temperature, the development of the irradiation tracks strongly reduces the anisotropy of the critical current density by varying the applied field orientation. Likewise, the Fp analysis highlights that irradiation defects behave as two-dimensional extended defects, which strengthen the point-pinning landscape active before irradiation. Conversely, approaching the transition temperature, the effectiveness of the irradiation-induced defects decreases and a widespread Jc and Fp worsening occurs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
